foo.rb

[1] pry(main)> ObjectSpace.each_object.inject([]) { |a, e| a << e if (e.class == Class && !e.ancestors.include?(Object)); a }
DEPRECATION WARNING: MissingSourceFile is deprecated! Use LoadError instead. (called from block in <main> at (pry):1)
=> [JbuilderTemplate,
 ActiveRecord::Type::Serialized,
 #<Class:0x007fd0789aac18>,
 ActiveRecord::Type::Time::Value,
 #<Class:0x007fd078a100e0>,
 Concurrent::SynchronizedDelegator,
 ActionDispatch::Response::Header,
 Sprockets::LegacyTiltProcessor,
 Sprockets::LegacyProcProcessor,
 ActiveSupport::ProxyObject,
 ActionDispatch::Routing::RouteWrapper,
 DidYouMean::ClassNameChecker::ClassName,
 SimpleDelegator,
 Delegator,
 BasicObject,
 Tempfile,
 #<Class:0x007fd079198538>,
 Jbuilder,
 #<Class:0x007fd0798461f0>,
 FactoryGirl::NullObject,
 ActiveRecord::ConnectionAdapters::PostgreSQLTypeMetadata,
 Concurrent::SerializedExecutionDelegator,
 SynchronizedDelegator,
 Builder::XmlEvents,
 Builder::XmlMarkup,
 Builder::XmlBase,
 Sidekiq::Extensions::Proxy,
 Redis::Future,
 ConnectionPool::Wrapper,
 OCI8EnhancedAutoRecover,
 #<Class:0x007fd07a6a1ce0>,
 ActiveRecord::AttributeMethods::TimeZoneConversion::TimeZoneConverter,
 #<Class:0x007fd07a6b8c38>,
 ActiveRecord::Locking::LockingType,
 #<Class:0x007fd07a75a588>,
 #<Class:0x007fd07c0486a8>,
 Mail::PartsList,
 Pry::LastException,
 FactoryGirl::Decorator::AttributeHash,
 FactoryGirl::Decorator,
 #<Class:0x007fd07c5648d0>,
 Pry::Byebug::Breakpoints::MethodBreakpoint,
 Pry::Byebug::Breakpoints::FileBreakpoint,
 FactoryGirl::Decorator::NewConstructor,
 FactoryGirl::Decorator::InvocationTracker,
 FactoryGirl::Decorator::DisallowsDuplicatesRegistry,
 FactoryGirl::Decorator::ClassKeyHash]